Investigation into the role of autophagy protease ATG4A in normal and impaired erythropoiesis

自噬蛋白酶 ATG4A 在正常和受损红细胞生成中的作用研究

• 批准号: 10558651
• 负责人: Massiel Chavez Stolla
• 金额: $ 14.8万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10558651
• 关键词: Acetylcysteine; Antioxidants; Autophagocytosis; Autophagosome; BCL-2 Protein; BCL2/Adenovirus E1B 19kd Interacting Protein 3-Like; Biology; Cell Differentiation process; Degradation Pathway; Development; Disease; Dysmyelopoietic Syndromes; Erythroblasts; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Ferritin; Genes; Hematological Disease; Hematology; Hematopoietic; Heme; Hemoglobin; Human; Impairment; International; Investigation; Iron; K-Series Research Career Programs; Knowledge; Laboratories; Mammalian Cell; Measures; Mediating; Mentorship; Metabolism; Mitochondria; Organelles; Oxidative Stress; Patients; Peptide Hydrolases; Preparation; Production; Proteins; Reactive Inhibition; Reactive Oxygen Species; Regulation; Reporter; Research Personnel; Role; Sideroblast; TFRC gene; Therapeutic Intervention; Tissues; Training; Universities; Washington; erythroid differentiation; experimental study; human model; improved; in vivo; induced pluripotent stem cell; inhibition of autophagy; macromolecule; metabolomics; mitochondrial dysfunction; model organism; mouse model; new therapeutic target; oxidation; progenitor; receptor; recruit; selective expression; stem cell model

PROJECT SUMMARY/ ABSTRACT Autophagy is a self-degradation pathway that has tissue-specific functions in erythropoiesis. During erythroid differentiation, autophagy facilitates the degradation of macromolecules and the programmed clearance of mitochondria. The long-term objective of this proposal is to determine how autophagy contributes to normal and impaired erythropoiesis. Patients with Myelodysplastic syndromes (MDS) often have impaired erythropoiesis and mitochondrial dysfunction. A subset of MDS, MDS with ring sideroblasts (RS), contain the aberrant accumulation of iron-laden mitochondria in erythroblasts suggesting that autophagy may be dysregulated in hematopoietic disorders and impair erythroid differentiation. While essential autophagy genes are known to contribute to autophagy in erythropoiesis, little is known about the tissue-specific regulation of autophagy during human erythroid differentiation. We have identified the selective expression of the autophagy protease ATG4A in the erythroid lineage. We have evaluated the contribution of ATG4A in an ex vivo model of human erythroid differentiation. Early in differentiation, ATG4A promotes the expansion and colony formation of erythroid progenitors. Late in differentiation, ATG4A promotes terminal maturation, enucleation, and mitochondrial clearance. Since ATG4 proteases are regulated by reactive oxygen species, the function of ATG4A in erythropoiesis may be sensitive to oxidative stress. Based on our preliminary results, we hypothesize that ATG4A mediates autophagy during early and late erythropoiesis and is dysregulated by oxidative stress. In aim 1, we will identify the role of ATG4A-dependent autophagy in early erythropoiesis. In aim 2, we will determine the mechanism of ATG4A-dependent mitochondrial clearance. In aim 3, we will examine the regulation of mitochondrial clearance in human models of MDS-RS. The experiments outlined in this proposal will be conducted under the mentorship of Dr. Sergei Doulatov, an expert in the development and use of human iPSC models to study erythroid disorders, and co-mentorship of Dr. Janis Abkowitz, Chair of the Division of Hematology at the University of Washington and international expert in MDS and erythroid biology. This career development award will support my training to become an independent investigator studying the contribution of autophagy to normal and dysfunctional erythropoiesis.

项目摘要/摘要 自噬是一种自我降解途径，在红细胞生成中具有组织特异性功能。在红细胞期间 差异化，自噬促进了大分子的降解和编程的清除率 线粒体。该提案的长期目标是确定自噬如何对正常和 红细胞生成受损。骨髓增生综合征（MDS）的患者通常会损害红细胞生成 和线粒体功能障碍。 MDS的子集，带环Sidoblasts（RS）的MD，包含异常 含铁的线粒体在红细胞中的积累，表明自噬可能失调 造血疾病和损害红细胞分化。虽然已知必需的自噬基因 有助于促红细胞生成的自噬，对自噬的组织特异性调节几乎不知道 人红细胞分化。我们已经确定了自噬蛋白酶ATG4A的选择性表达 在红细胞谱系中。我们已经评估了ATG4A在人类红细胞的离体模型中的贡献 分化。在区分的早期，ATG4A促进了红斑的扩张和菌落形成 祖先。分化后期，ATG4A促进末端成熟，摘除和线粒体 清除。由于ATG4蛋白酶受活性氧调节，因此ATG4A的功能 红细胞生成可能对氧化应激敏感。根据我们的初步结果，我们假设 ATG4A在促红细胞生成的早期和晚期介导自噬，并因氧化应激失调。目标 1，我们将确定AT​​G4A依赖性自噬在早期红细胞生成中的作用。在AIM 2中，我们将确定 ATG4A依赖性线粒体清除的机制。在AIM 3中，我们将检查 MDS-RS模型中的线粒体清除。该提议中概述的实验将是 在人类IPSC开发和使用专家Sergei Doulatov博士的指导下进行 研究红细胞疾病的模型，以及贾尼斯·阿布科维茨（Janis Abkowitz）博士的委托书 华盛顿大学血液学和MDS和红细胞生物学的国际专家。这个职业 发展奖将支持我的培训，成为研究的独立调查员，研究的贡献 自噬至正常和功能障碍性红细胞生成。